Should You Lock Your Knees On Squats

The first time I locked my knees during a squat, I felt a sharp, jarring pop in my knee — a sound I'll never forget. I was mid-exercise, trying to perfect my form. In that moment, I realized that locking your knees during squats is not just a common mistake, but one that can lead to serious injury. As a movement coach, I've seen this happen to more people than I can count, and it's a topic that comes up frequently in my classes and one-on-one sessions. The question 'should you lock your knees on squats' is more than just a technical detail; it's a crucial point that can protect your joints and keep you moving for years to come.

I remember the first time I noticed the difference between a squat with locked knees and one with a slight bend. The locked version felt rigid, almost unnatural, whereas the squat with a bit of knee flexion felt smoother, more balanced. That's when I started digging into the science behind knee locking and how it affects joint health, muscle engagement, and long-term mobility. It's not just about avoiding pain; it's about optimizing your movement for safety and effectiveness. Over the past few years, I've tested dozens of squat variations, and every time, I've found that keeping a slight bend in the knee is far more beneficial than locking it out.

Now, when I teach squats, I emphasize the importance of keeping a small amount of knee flexion at the bottom of the movement. It's a subtle but powerful adjustment that can prevent injury and improve performance. I've seen this change in my own body — less strain on my knees, better muscle engagement, and more stability in every rep. If you're someone who's been told to 'lock your knees' on squats, this article is for you. Let's explore the real reason behind this advice and how to squat safely — without locking your knees.

The Science Behind Knee Locking

As of August 2026, Knee locking occurs when the knee joint is fully extended at the bottom of a squat, and it's often encouraged by beginners or even some instructors. However, this position places excessive force on the knee joint, which can lead to wear and tear over time. I've seen this in my own body — when I lock my knees during a squat, I feel a significant increase in pressure on the knee cap. Can be uncomfortable even in the short term.

From a biomechanical perspective, locking the knee removes the slight bend that allows for natural shock absorption. This is especially important when performing squats with weight, as the knee joint needs to handle forces that can be up to 3-4 times your body weight. If you're not careful, this can lead to long-term damage, such as patellar tendinitis or meniscus tears.

In my own experience, using a slight knee bend during squats has significantly reduced the strain on my knees. I've noticed that I can perform more reps with better form, and I've avoided the sharp pain that used to come with locking my knees. This is backed by research — one study found that maintaining a 10-15 degree knee flexion at the bottom of the squat can decrease knee joint loading by up to 20%.

Why You Should Avoid Locking Your Knees

Locking the knee removes the natural cushioning that the joint relies on during movement. This can lead to microtrauma over time, especially if you're performing squats regularly. I've seen this happen to clients who thought they were training smart, but were actually creating long-term damage without realizing it.

One of the most surprising findings I've come across is that even slight knee locking can alter the mechanics of the squat, shifting pressure to the patellar tendon and increasing the risk of patellar tendinopathy. In my own practice, I've noticed that clients who avoid full knee extension report fewer knee-related complaints and better overall performance.

Locking the knee can also make it harder to maintain balance, especially when performing squats with weights. I've had clients who struggled with balance during heavy squats because they were locking their knees instead of keeping a slight bend. The result was instability, which led to poor form and increased injury risk.

Locking your knees isn't just about form — it's about longevity.

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The Benefits of Keeping a Slight Bend

Keeping a slight bend in your knees during squats allows for better joint alignment and stability. I've noticed that this position helps me maintain better control of my body, which is especially important when I'm working with heavier weights. It also allows for a more natural range of motion, which is crucial for long-term mobility.

In my own training, I've found that keeping a slight knee bend allows for better activation of the quadriceps and glutes. This not only makes the movement more effective but also helps prevent muscle imbalances over time. I've seen this in my clients as well — those who keep a slight bend tend to have better muscle engagement and fewer complaints about knee pain.

I've experimented with different squat techniques over the years, and I can confidently say that keeping a slight bend in the knees is the most effective way to perform a squat safely. This approach helps distribute the load more evenly and reduces the risk of injury, which is why I now recommend it to all my clients.

“The first time I locked my knees during a squat, I felt a sharp, jarring pop in my knee — a sound I'll never forget.”— Knee Friendly Cardio Routines editors

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How to Properly Perform a Squat Without Locking Your Knees

Proper squat form starts with maintaining a slight bend in your knees — around 10-15 degrees at the bottom of the movement. This allows for natural shock absorption and reduces joint stress. I've found that this technique helps me maintain better control during heavy squats and prevents the sharp pain that used to come with full knee extension.

To execute this properly, I recommend starting with bodyweight squats to build the foundational movement pattern. Once you've mastered the form, you can add weight gradually. I've seen clients who jump into heavy squats too quickly and end up with knee or back injuries because they didn't build the proper movement foundation first.

I also recommend using a mirror or recording your squats to ensure proper form. This has helped me catch small mistakes early on and make adjustments before they become habits. It's also a great way to track progress and ensure that you're maintaining the slight knee bend consistently.

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Common Mistakes and How to Avoid Them

One of the most common mistakes I've seen is locking the knees, which can put excessive pressure on the joint. I've had clients who thought they were doing squats correctly, only to realize later that they were locking their knees and creating long-term damage.

Another mistake is leaning forward too much, which shifts the weight to the lower back and reduces the effectiveness of the movement. I've noticed that clients who lean forward tend to have more back pain and less muscle engagement in the legs.

Improper foot positioning is another common issue. Many people point their toes too far out or in, which can lead to joint misalignment. I've experimented with different foot positions and found that a slight outward toe rotation (about 15-30 degrees) helps with stability and reduces knee strain.

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Should You Lock Your Knees On Squats